Apparatus for assembling sealed contact switches

ABSTRACT

APPARATUS FOR ASSEMBLING SEALED CONTACT SWITCHES HAS A NUMBER OF FIXTURES, EACH OF WHICH ARE INCREMENTALLY MOVED THROUGH EACH ONE OF A SERIES OF ASSEMBLY STATIONS. EACH FIXTURE HAS AXIALLY ALIGNED VERTICAL MOVING UPPER AND LOWER CARRIAGES FOR SUPPORTING AN UPPER AND A LOWER CONTACT, RESPECTIVELY. POSITIONED BETWEEN THE UPPER AND LOWER CARRIAGES ARE LATERALLY MOVABLE HOLDING FACILITIES FOR SUPPORTING A GLASS SLEEVE INTO WHICH ARE MOVED THE UPPER AND LOWER CONTACTS IN AN OVERLAPPING RELATIONSHIP. FACILITIES ARE PROVIDED ON THE FIXTURE TO MAGNETIZE THE UPPER CONTACT BY WAY OF THE UPPER CARRIAGE TO ATTRACT AND SUPPORT THE LOWER CONTACT WHICH IS SUBSEQUENTLY RELEASED BY THE LOWER CARRIAGE. THE LOWER CONTACT IS THEREAFTER SEALED BY   RADIANT ENERGY WITHIN THE LOWER END OF THE GLASS SLEEVE WHILE FORMING GAS IS INTRODUCED INTO THE UPPER END OF THE GLASS SLEEVE. SUBSEQUENTLY, THE HOLDING FACILITIES ARE ACTUATED TO MOVE THE GLASS SLEEVE AND SEALED LOWER CONTACT LATERALLY WITH RESPECT TO THE UPPER CONTACT TO SET A PREDETERMINED GAP BETWEEN THE OVERLAPPING PORTIONS OF THE UPPER AND LOWER CONTACTS. THEREAFTER THE UPPER CONTACT IS SEALED WITHIN THE UPPER END OF THE GLASS SLEEVE IN AN ENCLOSED PRESSURIZED CHAMBER.

Dec. 14, 1971 s. A. MARLIN Er AL 4 APPARATUS FOR ASSEMBLING SEALED CONTACT SWITCHES 4 Sheets-Sheet 1 Original Filed March 3, 1967 fare/afar. 5242214214. Afarlz'a J2me: afAcd'aznelt wlkelm'ld fmt'd'tj War/rely Dec. 14, 1971 a. A. MARLIN ETAL 3,626,511

APPARATUS FOR ASSEMBLING SEALED CONTACT SWITCHES Original Filed March 5, 1967 4 Sheets-Sheet l Dec. 14, 1971 MARLIN ETAL 3,626,511

APPARATUS FOR ASSEMBLING SEALED CONTACT SWITCHES Original Filed March 5, 1967 4 Sheets-Sheet s Dec. 14, 1971 MARUN EI'AL 3,626,571

APPARATUS FOR ASSEMBLING SEALED CONTACT SWITCHES Original Filed March 5, 1967 4 Sheets-Sheet 4.

United States Patent US. Cl. 29-203 4 Claims ABSTRACT OF THE DISCLOSURE Apparatus for assembling sealed contact switches has a number of fixtures, each of which are incrementally moved through each one of a series of assembly stations. Each fixture has axially aligned vertical moving upper and lower carriages for supporting an upper and a lower contact, respectively. Positioned between the upper and lower carriages are laterally movable holding facilities for supporting a glass sleeve into which are moved the upper and lower contacts in an overlapping relationship. Facilities are provided on the fixture to magnetize the upper contact by way of the upper carriage to attract and support the lower contact which is subsequently released by the lower carriage. The lower contact is thereafter sealed by radiant energy within the lower end of the glass sleeve while forming gas is introduced into the upper'end of the glass sleeve. Subsequently, the holding facilities are actuated to move the glass sleeve and sealed lower contact laterally with respect to the upper contact to set a predetermined gap between the overlapping portions of the upper and lower contacts. Thereafter the upper contact is sealed within the upper end of the glass sleeve in an enclosed pressurized chamber.

This application is a division of US. Pat No. 3,539,323, issued Nov. 10, 1970, and entitled Apparatus for Assembling Sealed Contact Switches.

BACKGROUND OF THE INVENTION Assembly machines such as that disclosed in N. F. Gubitose et al. Pat. 3,273,989, are available for making sealed contact switches. However, these machines require the use of rather large, complex, and expensive mechanisms to properly fabricate switches within desired manu facturing tolerances. It is desirable to manufacture such switches using improved apparatus which is smaller, simpler, and less expensive.

An object of this invention is to provide new and improved apparatus for assembling sealed contact switches.

It is a further object of this invention to provide new and improved apparatus for assembling sealed contact switches having facilities to direct a controlled atmosphere into a glass sleeve.

Another object of this invention is to provide an assembly fixture having new and improved facilities in the upper carriage to securely hold an upper contact having an irregular shape.

It is a further object of this invention to provide an assembly fixture having new and improved facilities for latching one of its carriages open to release the contact held therein.

Another object of this invention is to provide an assembly fixture having new and improved facilities for maintaining its movable carriages in constant engagement with a reference side of a support.

Patented Dec. 14, 1971 ice SUMMARY OF THE INVENTION With these and other objects in view, the present invention contemplates an apparatus including an upper and a lower carriage for holding an upper and a lower contact respectively and a glass sleeve holder positioned between the carriages. The carriages are moved along a standard from a position spaced from the glass sleeve holder to positions adjacent the glass sleeve holder, whereat the contacts are positioned within the glass sleeve in overlapping relationship. The upper carriage includes an inner jaw, having a pivotal mounted member thereon, and an outer jaw movable toward and away from the inner jaw for supporting the upper contact. Formed in the inner jaw of the upper carriage is an aperture which is aligned with a gas passageway formed in the standard when the upper carriage is in a position adjacent the glass sleeve holder. The gas passes through the aperture to a channel formed in the outer jaw. The channel functions to receives a portion of the upper contact and to direct gas downwardly into the glass sleeve. The lower carriage includes an inner jaw and an outer jaw pivotally mounted for movement toward and away from the inner jaw for holding the lower contact. Facilities are provided which are rendered effective by the outer jaw of the lower carriage being pivoted away from the inner jaw for latching the outer jaw from the inner jaw to release the lower contact.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a completed sealed contact switch;

FIG. 2 is a plan view of the assembly apparatus showing a plurality of assembly fixtures mounted on an indexable turret and illustrating the various assembly stations involved in the fabrication of a sealed contact switch;

FIG. 3 is a perspective view of an assembly fixture embodying the principles of the present invention;

FIG. 4 is an exploded cross-sectional view of the upper carriage and its mounting to the assembly fixture;

FIG. 5 is a partial perspective view of the lower carriage and the facilities for latching the jaws of the lower carriage open; 1

FIG. 6 is an exploded partially cross-sectioned view of the assembly fixture illustrating the magnitizing facilities extending through the upper jaw, the forming gas passageways, and the pivotal member on the outer jaw for securely holding the upper contact;

FIG. 7 is a view taken along line 7-7 from FIG. 6, further illustrating the way in which the upper contact is held by the upper jaws;

FIG. 8 is a view taken along line 8-8, from FIG. 6, illustrating the mechanism for setting a predetermined gap between the upper and lower contacts;

FIG. 9 is an exploded side elevational view of the jaws of the upper carriage holding a contact having an exaggerated defect in the shank portion thereof;

FIG. 10 is an exploded side elevational view showing the defective contact of FIG. 9 as held within a pair of rigid jaws;

FIG. 11 is a view taken along line 11-11, from FIG. 6 illustrating the positioning of a radiant energy source with respect to the lower reflector of the assembly fixture; and

FIG. 12 is an exploded, partial perspective view of the upper jaw assembly.

3 DETAILED DESCRIPTION In FIG. 1, there is shown a completed sealed contact switch having an upper contact 21 and a lower contact 22 sealed within a glass sleeve 23. The upper contact 21 has a shank portion 24 and a flat paddle portion 26 which overlaps a flat paddle portion 27 of the lower contact 22 which has a shank portion 28.

The assembly apparatus used in fabricating a sealed contact switch 20 includes a plurality of assembly fixtures 31 mounted to an indexable turret 32, as shown in FIG. 2.

A support platform or table 33 is concentrically mounted with respect to the turret 32 and has mounted thereon various facilities which cooperate with the assembly fixtures 31 in the assembly of the sealed contact switch 20. Each indexing step of the turret 32 brings an assembly fixture 31 into alignment with one of the facilities mounted to the table 33. Each indexing step hereinafter is referred to as an assembly station and is numbered accordingly on FIG. 2.

OPERATION IN GENERAL At station 1, an upper and a lower contact 21 and 22 are inserted in proper orientation by a contact loading assembly into jaws mounted to upper and lower carriages which are movable on the fixture 31. The turret 32 then indexes the assembly fixture 31 to station 2 where a glass sleeve loading assembly 29 inserts a glass sleeve 23 into a sleeve holder mounted to the fixture 31. After the sleeve 23 is inserted in the sleeve holder, the upper and lower carriages are moved toward each other to insert the contacts 21 and 22 into the glass sleeve 23 in spaced overlapping relationship. At this point, pressurized forming gas is introduced into a passageway in the bottom of the fixture 31 which communicates with the upper end of the open glass sleeve 23 to permit gas to flow into the glass sleeve.

The turret 32 then indexes to station 3 where a radiant heater 30 is energized to preheat the lower end of the glass sleeve 23 and the lower contact 22. The radiant heater cooperates with a reflector mounted on the fixture 31 in a position behind the lower portion of the glass sleeve 23. This preheating reduces the cycle time necessary in fabricating a switch. It is not necessary, however, that the preheat stations be utilized. The fixture 31 may be held in alignment with a radiant heater for a suflicient time to accomplish the seal without a separate preheating station.

Fixture 31 then indexes to station 4 where a coil mounted on the assembly fixture 31 is energized to magnetize the upper contact 21 so that it attracts and supports the lower contact 22 whereupon the lower carriage of the fixture 3'1 releases the lower contact 21 and is latched in an open position. Another radiant heater is then energized to complete the seal of the lower contact within the lower end of the glass sleeve.

In the fabrication of a sealed contact switch, it is advantageous to first seal the bottom contact within the glass sleeve, rather than first sealing the upper contact within the upper end of the glass sleeve. In particular, When the bottom contact is sealed first, the upper contact can be securely held by the upper carriage while the lower contact is magnetically held and supported by the upper contact. If the upper seal is made first, than it is necessary for the upper carriage to release the upper contact permitting it to be held only by magnetic attraction to the lower contact. When this is done, the upper contact has a tendency to tip, resulting in improper positioning of the upper contact with respect to the glass sleeve. By sealing the lower contact first, the upper contact is held securely by the upper carriage thereby eliminating the tendency of the upper contact to tip. Likewise, the lower contact is suspended downwardly and also has no tendency to tip.

The fixture then indexes to station 5 where another radiant heater preheats the upper end of the glass sleeve and the upper contact. At this point, air is introduced into another passageway in the bottom of the fixture to actuate a piston mouned to the fixture to move the glass sleeve holder, the glass sleeve 23, and the sealed lower contact 22 laterally with respect to the upper contact 21 to accurately set a predetermined gap between the overlapping portions of the upper and lower contacts. The fixture 31 then indexes to the next station 6 where a hood 45 is lowered over the fixture to form an enclosed chamber into which pressurized air is introduced. To decrease the cycle time of the assembly apparatus, it may be desirable to have an individual hood associated with each fixture, as disclosed in Gubitose et al. Pat. 3,273,989, so that the turret 32 may be indexed while a switch is held in a pressurized chamber. After pressurization, another radiant heater 59 is energized to complete the upper seal. The flow of forming gas, which has continued during the sealing operations, is stopped immediately upon completion of the upper seal. Hood air pressure is then increased slightly to prevent bubbling of the glass sleeve caused by expansion of the gas confined within the sealed sleeve. The fixture 31 then indexes to a cooling station 7 and then to a final unloading station 8 where the completed switch 20 is withdrawn from the fixture 31 by an unloading assembly 75.

ASSEM BLY FIXTURE Referring now to FIG. 3, there is shown an assembly fixture 31 having a base 34 and a vertical standard 36 mounted thereto. An upper and a lower carriage 37 and 38, respectively, are movably mounted on the standard 36. The carriage 37 has an upper jaw assembly 39 which includes a rigid inner jaw 41 and a pivotally mounted outer jaw 42 having a lobe 43 at the upper end thereof which cooperates with facilities, such as an air cylinder mounted to the table 33, for opening the jaws 41 and 42. A spring 44 is mounted behind the lobe 43 of the outer jaw 42 to maintain the upper jaw assembly 39 in a normally closed position.

The lower carriage 38 includes a lower jaw assembly 46 having a rigid inner jaw 47 and a pivotally mounted outer jaw 48 having a lobe 49 at its lower end thereof. A spring 51 is positioned between the inner jaw 47 and the outer jaw 48 to maintain the lower jaw assembly 46 in a normally closed position. Positioned intermediate the upper and lower carriages 37 and 38, respectively, and mounted to the standard 36 is a glass sleeve holder 52 which is movable laterally between a first and a second position by gap adjusting facilities designated 53 to be described more fully hereinafter. An upper reflector 54 is mounted to the standard 36 and is positioned such that it encompasses an upper portion of the glass sleeve 23 held within the holder 52. The reflector 54 has a cutout portion 56, permitting the jaw assembly 39 to be moved downwardly to its lowest position, set by adjustable stops, not shown, but which may be, for example, a screw, such as screw 50, shown on the lower carriage 38 in FIG. 5. The cutout portion 56 permits the carriage 37 to be moved to its proper position adjacent the glass sleeve 23 without striking the carefully positioned reflector 54. Likewise, a lower reflector 57 is mounted beneath the sleeve holder 52 and has a cutout portion 58.

Referring to FIG. 6, there is shown a coil 55 mounted behind the standard 36 and has a magnetizable core or tube 60, made of a material, such as Permalloy, mounted within the coil 55. The core 60 extends through an aperture 76 in the standard 36 which terminates at an opening 77 immediately above the upper reflector 54. The core 60 is hollow to permit forming gas to flow therethrough. The inner jaw 41 also has a hollow magnetizable tube 65 inserted therein which lines up with the opening 77 (see FIG. 3) when the upper carriage 37 is moved to its lowest position. When the coil 55 is energized and the tube 65 is aligned with opening 77, the upper contact 21, held within the upper jaw assembly 39, is magnetized,

causing the attraction of the overlapping portion 27 of the lower contact 22 thereto (see FIG. 1). At this time, the lower carriage 38 releases the shank portion 28 of the lower contact 22 so that the lower contact is solely supported by the upper contact 21. It is to be noted that the magnetic field is transmitted to the upper contact 21 only when the tube 65 in the inner jaw 41, is in alignment with the opening 77 and when the coil 55 is energized.

Referring now to FIG. 4, there is shown the upper carriage 37 mounted on the standard 36 which has a beveled surface 61 on the rear side thereof. A roller 62 having a complementary beveled periphery, is fixed to the shaft 67 which is rotatably mounted to the carriage 37. A spring 63 urges a member 68 against an enlarged end of the shaft 67 which in turn urges the roller 62 against the beveled surface 61. The roller 62 is urged against the beveled surface 61 to provide sufficient frictional force between the carriage 37 and the standard 36 to prevent relative movement therebetween except by the application of external forces to the carriage 37. In addition, the resultant force of the beveled roller 62 acting against the beveled surface 61 causes a side plate 64 of the carriage 37 to wear against a side surface 66 of the standard 36 and causes the surface 69 of the inner jaw 41 to wear against the adjacent surface 70 of the standard 36. This permits the carriage 37 and its corresponding jaw assembly 39 to be accurately positioned with reference to the surfaces 66 and 70 of the standard 36 at all times regardless of wear or dimensional changes due to thermal expansion of any part of the apparatus.

As shown in FIGS. 3 and 5, the base 34 of the assembly fixture 31 has three holes therethrough 71, 72, and 73 which are in alignment with corresponding holes (not shown) in the turret 32. Tubing (also not shown) connects these holes in the turret 32 to a plurality of valves and gas manifolds which regulate the flow of gas through the holes 71, 72, and 73 at prescribed times during the assembly cycle of the apparatus. A tube 74 connects the hole 71 in the base 34 with the hollow core 60. As shown in FIG. 6, the inner jaw 41 has a hollow tube 65 therethrough, which when aligned with the core 60 permits forming gas to flow through tube 74 into the upper end of the glass sleeve 23.

Referring to FIGS. 6, 7, and 12, the outer jaw 42 of the upper jaw assembly 39 has a channel 81 formed therein which fits over a projecting portion 82 on the inner jaw 41. A contact 21 is held by its shank 24 between the fiat surface of the projecting portion 82 and a member 83 which is pivotally mounted on a pin 84 in the channel 81 of the outer jaw 42. The member 83 is shorter than the depth of the channel 81 so that the sides 86 of the jaw 42 fit over the projection 82 on the lower jaw 41. This provides a relatively enclosed passageway 87 surrounding the shank portion 24 of the contact 21. Thus, gas flowing through the hollow core 60 and tube 65 is directed into the channel 81 of the outer jaw 42 and then downward through the passageway 87 into the glass sleeve 23.

The pivotal member 83 is provided to compensate for any irregularities or defects in the shape of the shank of a contact. Referring now to FIG. 9, there is shown a contact 21 having a shank portion 24 which has a greatly exaggerated irregularity 89 formed therein which may result, for example, from burrs on the material or variations in the diameter of the shank. The outer jaw 42 engages the shank 24 between the projecting portion 82 and the two extensions 78 of the pivotal member 83. The member 83 pivots to follow the contour of the shank 24 as closely as possible thereby providing maximum contact between the two jaws 41 and 42 to hold the contact 21 securely. If only a rigid outer jaw were provided, such as jaw 85, shown in FIG. 10, a contact 21 having the irregularity 89 would be gripped with only point contact on one jaw thereby permitting movement of the contact within the jaws 41 and 85. It is clear that in assembly apparatus of this type, the upper contact 21 must be held very accurately and securely in the position in which it is loaded, since the position of the upper contact 21 is the reference position for the lower contact 22; that is, the

- ultimate position of the lower contact is determined by the position of the upper contact.

Referring now to FIG. 5, there is shown the lower carriage 38 with the lower jaw assembly 46. A beveled roller 90 is mounted to the carriage 38 and cooperates with the beveled surface 61 of the standard 36, the same as was previously described for roller 62 (see FIG. 4). The lower jaw assembly 46 is substantially the same as the upper jaw assembly 39 (see FIG. 6) except that it has no magnetizing facilities or forming gas flow facilities. A latching arm or latch 91 having a projection 92 at one end and a cam surface 93 formed at the other end is pivotally mounted by pin 94 to the lower carriage 38. A cam 96 is stationarily mounted to the base 34 of the assembly fixture 31. When the carriage 38 is moved downwardly, the cam 96 engages the surface 93 and pivots the arm 91 clockwise thereby moving the projection 92 out from between the outer jaw 48 and inner jaw 47, thus permitting the jaws to close. When the carriage 38 is moved upwards the jaws remain in their closed position until an air cylinder (not shown) is actuated to engage the lobe 49 to open the jaws whereupon a spring 97 urges the latch 91 counterclockwise so that the projection 92 is inserted between the inner jaw 47 and the outer jaw 48 to maintain the jaws open until the carriage 38 is again moved downwardly. The use of latch 91 permits the lower jaw assembly 46 to open immediately after the magnetization of the upper and lower contacts, and remain open for the remainder of the assembly cycle without the necessity of having extraneous facilities, such as a cam surrounding the periphery of the turret 32, continue to engage the lobe 49.

Referring now to FIG. 8, there is shown a view illustrating in detail the gap adjusting facilities 53 and the sleeve holder 52. The glass sleeve 23 (see FIG. 1) is inserted into a groove 98 formed in the sleeve holder 52. A roller 99 is urged by a spring 101 into the groove 98 and serves to resiliently hold the glass sleeve 23 when loaded therein. Any resiliently mounted member could be used to hold the glass sleeve. The glass sleeve holder 52 is mounted to a block 102 which is movable laterally. A dual piston air cylinder 104 is mounted behind the glass sleeve holder 52 as shown in FIGS. 3 and 6. The cylinder 104 has two bores 105 and 106 therein in which pistons 107 and are slidably mounted. The ends of the pistons 107 and 110 are adjacent to a pair of levers 113 and 114, each of which have their other ends in engagement with the sliding block 102. Levers 113 and 114 are pivotally monuted at 116 and 117, respectively, to a stationary member 115. When pressurized air is introduced into an aperture 108 which communicates with bore 105, the piston 107 moves outwardly pivoting lever 113, which urges the block 102 and sleeve holder 52 to the left, as viewed in FIG. 3. Aperture 108 is connected to a tube 112 which communicates with passagewav 73 in the base 3 of the assembly fixture, as shown in FIG. 5. Aperture 109 is connected to a tube 111 wh ch communicates with the passageway 72 in the base 34 as shown in FIG. 3. The introduction of air into either tube 111 or 112 c uses either piston 107 or piston 110 to pivot a lever 113 or 114 to move the block 102. which correspondin ly moves the glass sleeve holder 52. The movement of the block 102 is limited by an adjusting screw 122 which is inserted in a threaded aperture 123 in block 115. The screw has a tapered end 124 which fits within a tapered bore 126 in the sliding block 102. By adjusting the amount that the tapered end 124 extends into the bore 126, it is possible to accurately limit the distance which the sliding block 102 and the glass sleeve holder 52 move. This sliding or shifting movement of the holder 52 is used to properly and accurately set the gap between the overlapping paddle portions 26 and 27 of the upper and lower contacts 21 and 22 respectively after the bottom contact 22 is sealed within the glass sleeve. The sequence of operation of the gap adjusting facilities 53 is described more fully in the description of the complete operation of the apparatus.

In FIG. 11, there is shown one of the radiant energy sources 35 which includes a lamp 118, such as an infrared energy, quartz-iodine lamp, mounted at one of the foci of a semi-elliptical reflector 119. The reflector 119 focuses the radiant energy onto a lower portion of the glass sleeve 23, in a manner such as disclosed, for example, in R. M. Pinkham et al. Pat. 3,282,669. The lower reflector 57 partially encompasses the lower portion of the sleeve 23 so as to direct radiant energy onto the portion of the glass sleeve 23 which does not directly receive radiant energy generated and focused by the lamp 118 and reflector 119. The reflector 57, and likewise reflector 54 (see FIG. 3), are adjustable in order to provide a uniform distribution of radiant energy about the periphery of the glass sleeve. In FIG. 3, a screw 121 is shown which can be loosened to permit reflector 54 to be moved until the desired uniform distribution of energy is provided. The reflector 57 has a similar adjusting screw, which is not shown. It is to be noted that all of the radiant energy sources including 30, 35, 40, and 59 as shown in FIG. 2, are similar in structure to source 35 described above. However, radiant energy sources 40 and 59 are positioned vertically higher than sources 30 and 35 in order to be in alignment with the upper reflector 54 and an upper portion of the glass sleeve 23.

OPERATION At the beginning of a cycle of operation, the assembly fixture 31 has its upper and lower carriages 37 and 38, positioned respectively against an upper stop 79 and a lower stop 80, as shown in FIG. 3. At this point, both jaw assemblies 39 and 46 are closed. The turret 32 indexes eight times to make a complete revolution. Each indexing step is referred to as a station and is numbered accordingly on FIG. 2.

At station 1, a pair of air cylinders (not shown) mounted to the support table 33 are actuated to engage the lobes 43 and 49 of the upper outer jaw 42 and the lower outer jaw 48, respectively, to open the jaws. The air cylinders are positioned angularly with respect to the standard 36 so that a component of force on the upper jaw assembly 39 acts to hold the upper carriage 37 against stop 79, as well as causing the outer jaw 42 to pivot and open. Similarly, the lower air cylinder is positioned to hold the lower carriage against stop 80 as well as to open the jaw 48. While the outer jaws 42 and 48 are open, an upper contact 21 and a lower contact 22 are inserted in proper orientation by the contact loading assembly 25 which is mounted to the table 33 in alignment with station 1. In response to the introduction of the contacts between the jaws, the air cylinders are de-actuated thereby permitting the outer jaws 42 and 48 to engage the shanks 21 and 28 of the upper and lower contacts 21 and 22, respectively, to grip the contacts and hold them securely. After the contacts are gripped by the jaws, the contact loading assembly 25 is retracted and the turret 32 indexes the assembly fixture 31 to station 2.

At station 2, a glass sleeve 23 is loaded by the sleeve loading assembly 29 into the grove 98 of the sleeve holder 52 and is held therein by the resiliently mounted roller 99 (see FIG. 8). At this point, the glass sleeve holder 52 is positioned as far leftward as possible, viewing the fixture 31 as shown in FIG. 3. Air cylinders, stationarily mounted to the table 33 at station 2, are then actuated to move the upper and lower carriages 37 and 38 toward each other. It is to be noted that the contacts 21 and 22 are loaded into the jaw assemblies in mis-alignment with one another so that they move into the glass sleeve in overlapping relationship. Furthermore, at station 2, forming gas is permitted to flow through tube 74, core 60, and tube 65, into the upper end of the glass sleeve 23 (see FIG. 6). The turret 32 then indexes to station 3.

At station 3, the radiant energy source is energized to direct focused radiant energy against the lower end of the glass sleeve 23 to preheat the glass sleeve and the lower contact 22. The radiant source 30 cooperates with the stationarily mounted lower reflector 57 which is adjustable toward and away from the source 30 to achieve a uniform distribution of energy around the peripheral portion of the glass sleeve which is to be heated. This preheating step helps to reduce the cycle time in assembling a switch; however, it is not necessary that such a step be included. Accordingly, if desirable, station 3 may be eliminated. The turret 32 then indexes to station 4.

At station 4, an air cylinder is actuated to force the carriage 38 upward as viewed in FIG. 3 in order to insure that the carriage has not lowered during the indexing of the fixture from one station to another, such as may be caused by vibration of the apparatus. This makes certain that the lower contact 22 is properly positioned within the glass sleeve 23, prior to scaling, and that its paddle portion 27 properly overlaps the paddle portion 26 of the upper contact 21. At this station, the electrical contacts 127 (see FIG. 3) for the coil 55, engage stationary contact (not shown) to energize the coil 55 (see FIG. 6) to magnetize the upper contact 21 through the core 60 and tube 65, as previously described. The magnetized upper contact 21 attracts the overlapping portion of the lower contact 22 to support and hold the lower contact. Referring now to FIGS. 5 and 6, another air cylinder is then actuated to move the outer jaw 48 away from the inner jaw 47, thereby permitting the spring loaded latch 91 to move between the inner jaw 47 and outer jaw 48 to latch the jaws in an opened position shown as dotted line in FIG. 6. The lower contact 22 is then supported only by the magnetic forces of the upper contact 21. Then radiant source is energized and the radiant energy is focused by the reflectors 119 and 57 to uniformly distribute the energy about the lower peripheral portion of the glass sleeve 23 to heat and melt the glass to seal the lower contact 22 within the glass sleeve 23. The lower jaw assembly 46 remains in its uppermost position adjacent to the lower reflector 57 during the sealing of the lower contact 22 within the glass sleeve 23. The open jaws 47 and 48 permit the round shank 28 of the lower contact 22 to rotate about its axis or to move parallel to the faces of the jaws 47 and 48 so that the overlapping paddle portions of contacts 21 and 22 are in complete contact with each other; however, the jaws limit movement of the contact 22 perpendicular to the faces of jaws 47 and 48. It is to be noted that the form ing gas has been flowing through the glass sleeve 23 since station 2 and continues to flow. Turret 32 then indexes fixture 31 to station 5. The upper contact 21 remains magnetized at this time.

At station 5, radiant source is energized to preheat the upper end of the glass sleeve 23 in cooperation with the upper reflector 54. After preheating, the turret 32 is then indexed to station 6. At a position between station 5 and station 6, facilities (not shown), such as a cam, open a valve to introduce air into passageway 109 (see FIG. 8) to force the piston 110 outwardly, pivoting lever 114 to force the sliding block 102 and the glass sleeve holder 52 to the right as viewed in FIG. 3. This moves the glass sleeve 23 and the sealed lower contact 22 a predetermined distance away from the upper contact 21, which is still held in the upper jaw assembly 39, to set the gap between the overlapping paddle portions 26 and 27 of the contacts. Simultaneously therewith, the coil 55 is de-energized to release the overlapping portions of contacts 21 and 22.

At station 6 (FIGS. 2 and 6), a hood is lowered over the fixture 31 to provide an enclosed chamber which is pressurized with air. The purpose of the pressurized chamber is to achieve a gas pressure inside the completed switch which is suflicient to eliminate arcing at the required operational voltage level. Then radiant energy source 59 is energized and radiant energy is focused and directed through a window 128 in the hood 45 to make the upper 9 seal. Forming gas continues to flow through tube 74, core 60, and tube 65 into the glass sleeve 23 until the upper seal is made, whereupon the flow of forming gas is immediately stopped to prevent dimpling or deformation of the seal. Simultaneously, when the upper seal is made, the air pressure within the hood is increased slightly to compensate for the increase in the pressure of the forming gas sealed inside the glass sleeve to prevent bubbling of the glass sleeve 23. The radiant source 59 is also deenergized upon making the seal. After a predetermined time, the hood pressure is released, the hood raised, and the fixture 31 indexed to station 7, where the assembled switch 20 is permitted to cool. The turret 32 then indexes the fixture 31 to station 8.

At station 8 (FIGS. 2, 3, and 8), stationarily mounted air cylinders, not shown, are actuated to move the carriages 37 and 38 away from each other toward their respective stops 79 and 80. As the carriages are moved, the jaws 42 and 48 are pivoted to open so that they move freely past the shank portions 24 and 28 of the upper and lower contacts. While the outer bottom jaw 48 is already held open by the latch 91, it is nevertheless opened further to permit the projection 92 of the latch 91 to move out from between jaws 47 and 48 without restriction when cam 96 engages the cam surface 93 and pivots the latch 91 during downward movement of the carriage 38. Then the unloading assembly 75 is actuated to engage the glass sleeve and gently remove it from the sleeve holder 52 and deposit it in a bin. The fixture then indexes to station 1. At a position between station 8 and station 1, a valve is actuated to direct air into passageway 108 to move the glass sleeve holder 52 back to its initial leftward position to receive the next glass sleeve 23. This completes one cycle of operation.

It is to be understood that the above-described apparatus is simply illustrative of an application of the principles of the invention. Numerous other modifications to the apparatus and its operating cycle may be made by persons having ordinary skill in the art without departing from the spirit and scope of the invention.

What is claimed is:

1. In an apparatus for assembling a sealed contact switch having an upper and a lower contact sealed within a glass sleeve, said apparatus including a glass sleeve holder and upper and lower carriages for holding upper and lower contacts, respectively, said carriages being movable from positions spaced from said glass sleeve holder to positions adjacent to said glass sleeve holder wherein said contacts are positioned within said glass sleeve in overlapping relationship, the improvement which comprises:

a vertical standard upon which said carriages are movably mounted, said standard having a gas passageway therethrough;

said upper carriage having an inner jaw and an outer jaw movable toward and away from said inner jaw;

said inner jaw having an aperture therethrough positioned such as to be in alignment with said gas passageway when said upper carriage is in the position adjacent to 'said glass sleeve holder, said inner jaw having a projection formed thereon against which said upper contact is positioned;

said outer jaw having a channel formed therein for receiving a portion of said projection and for receiving gas flowing through said aperture to direct said gas downwardly into a glass sleeve; and

a member pivotally mounted in said channel of said outer jaw for holding said upper contact securely against said projection on said inner jaw.

2. In an apparatus for assembling sealed contact switches having an upper and a lower contact sealed within a glass sleeve, said apparatus including a glass sleeve holder and upper and lower carriages for holding an upper and a lower contact, respectively, said carriages being movable from loading positions spaced from said glass sleeve holder to sealing positions adjacent to said 10 glass sleeve holder wherein said contacts are positioned in overlapping relationship within said glass sleeve, the improvement which comprises:

jaw means mounted to said lower carriage for receiv ing a lower contact, said jaw means including an inner jaw and an outer jaw pivotally mounted for movement toward and away from said inner jaw;

means for urging said outer jaw toward said inner jaw;

means rendered effective by the outer jaw being pivoted away from the inner jaw for latching said outer jaw in a position spaced from said inner jaw; and

means responsive to the movement of said lower carriage from said sealing position to said loading position for unlatching said outer jaw.

3. In an apparatus for assembling sealed contact switches having an upper and a lower contact sealed within a glass sleeve, said apparatus including a glass sleeve holder and upper and lower carirages for holding an upper and a lower contact, respectively, said carriages being movable from positions spaced from said glass sleeve holder to positions adjacent to said glass sleeve holder wherein said contacts are positioned within said glass sleeve in overlapping relationship, the improvement which comprises:

jaw means mounted to said lower carriage for holding said lower contact, said jaw means including an inner jaw and an outer jaw mounted for movement toward and away from said inner jaw;

a latching arm pivotally mounted to said lower carriage, said latching arm having a projection on one end thereof of sufficient thickness to maintain said inner and outer jaws open when interposed therebetween, said latching arm having a cam surface formed on the other end thereof;

resilient means for urging said projection on said latching arm between said inner and outer jaws; and

a cam positioned to engage said cam surface of said latching arm when said carriage moves from said position adjacent to said glass sleeve holder to said position spaced from said glass sleeve holder to pivot said latching arm to withdraw said projection from between said inner and outer jaws to permit said jaws to close.

4. In an apparatus for assembling sealed contact switches having an upper and a lower contact sealed within a glass sleeve, said apparatus having a glass sleeve holder and upper and lower carriages for holding upper and lower contacts, respectively, said carriages being m0vable toward and away from said glass sleeve holder, the improvement which comprises:

a vertical standard having a beveled surface formed therein, said carriages being mounted for movement on said standard;

a roller having a corresponding bevel on the periphery thereof rotatably mounted to each of said carriages for engagement with said beveled surface of said standard; and

resilient means for urging said beveled periphery of said roller against said beveled surface of said standard to provide sufficient frictional force between said carriage and said standard to prevent relative movement therebetween except by the application of external forces thereto and to maintain the carriage in constant engagement with reference sides of said standard.

References Cited UNITED STATES PATENTS 2,755,760 7/1956 Fermanian et al. 29-203 J 3,061,144 10/1962 Brewer et al 221-13 3,273,989 9/1966 Gubitose et al. 65-l54 THOMAS H. EAGER, Primary Examiner US. Cl. X.R. 29-203 D 

